LONDON — King Charles III and his wife, Queen Camilla, were crowned in London on Saturday in an elaborate spectacle full of pomp and ceremony. More than 2,200 guests from around the world — including first lady Jill Biden — joined the royal family at the historic Westminster Abbey for the first coronation in 70 years while crowds of spectators lined the streets to watch the procession through the city. The ceremony featured medieval traditions and included modern touches — with non-Christian-faith leaders playing an important role — as Buckingham Palace seeks to project a more inclusive image at a time when younger generations, and many Commonwealth countries around the world, are questioning the future of the monarchy.